Absolute permissive block-signaling system



F. L. DODGSON.

ABSOLUTE PERMISSIVE BLOCK SIGNALING SYSTEM.

APPLICATION FILED OCT. 15. 1915.

1,384,521. Patented July 12,1921.

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* PATENTrOFFICE j FRANK L. noneson, ornocnns'rns, ew Yonn, Assreivon TO eENnn LnAILwnY I SIGNAL COMPANY, or earns, NEW YonK, A conronA'rronzor NEW YORK.

ABsoLuTn rnnivrissrvn BLocicsmNALiNe SYSTEM.-

Specification of Letters wa Pat t d ulyjt12 a Applicationvfiled October 15, i915. s arm. 56,047. a

To all whomit may concern Be it known that I, FRANK L. DODGSON, a citizen of the United States, ,and resident of the city offRochester, in the county of Monroe and IStateof New York, have invented a new anduseful Absolute Permissive Block-Signaling System, of which the following is a specification. Th1s lnventlon' relates to circuits for block signaling systems for governing railway trafiic, and more particularly to circuits which find a very useful application in block signaling systems for single track roads. 7

One of the objectsof this invention is to devise an arrangement of circuits for single track block signalingsysteins by means of which a train entering upon astretch of single 7 track between two passing sidings will cause.

signals to be displayedwliich will prevent the entrance of a'train onsaid stretch of track from the otherend thereof and which will afford adequate head-on and following protection for the train as it passes through said stretch of track without, however, un-.

necessarily delaying. trafiic.

A further objectof the invention is to devise an arrangement ofcontrolling circuits for a block signaling system, whereby a signal may be controlled effectively by simple and durable apparatus and causedto assume different ZLSPBCiJSiLCCOICllDg to the C lirection in which thetrain ".is traveling as it passes said signal.

A further objeetof the invention is to accomplish the objects enumeratedand other I objects which will appear inore'fully as the description of the invention progressesby s means of apparatus and controlling circuits therefor which are constructed in accordance r with principles found through long trial to be safe and reliable.

- Further objects and advantages will appear the description of the lDVGHUOIl progresses', andthe novel features of themvention will be particularly pointed out in the appended claims. I

In general; the invention consists in p'rovidinga suitable arrangement of electrical devices? and controlling circuits therefor, in connection with the well known block s1 gnalsystem employingnormally closed track circuits, whereby these devices 'are responsivef'to the direction of the movement of trains overa given part of the track.

The invention further consists in the parts," and in the arrangements and combi nations of parts, together withjthe controll h aresetforth ing circuits therefor whic fully at length hereinafter.

In describingthe inventionin detail, ref

erence": is hadfto the accompanying drawnate corresponding parts throughout the several views, and in WhlClli The single figureis a diagrammaticillus tration of a stretch of slngle track having invention, the operating parts of said. dc-i vices and said controlling circuits being of said stretch' of track. 1

shown in their normal. conditions existing when there 18111013111111 presentfon any part ing, wherein I have illustrated a preferred physlcal embodlment' ofmy 1nventi0n,' and wherein l ke characters of reference desig- Referring Itothe accompanying drawing; the two track railsl and 2 of the stretch] of track between thepassing sidings S are one end of'said sections, and at the other Bare connected across said tr ack'rails.

in the art of railway signaling'without further explanation. The two track sections B bv the arrows \X and Y.

At the'lefthand end of the block A is ends'of said sections track relays 5, 6, 7, igid; he track battery 4 and the track relay of each track section, together with the track rails H thereof constitute thewell known normally closedtrack circuit, the operation! of which will' be clearly understood by those skillml} 8O dividedby suitable insulating joints 3 into; a i a series of track sections of which four are shown'and designated A B C, and D. Each; of'these track sections has" a trackbattery-t connected across the track rails 1 and 2st and C together fornroneoffthe so called blocks, and the combinedlengthof said two I track sections is substantially the same asthelength of each ofthetrack sections and'D, so that effect, there are three blocks] AfBC, and D. Traffic over this stretch of: track 'maybe'in either direction as indicated located a signal 9 which governs traffic in and 12 at the ends of the stretch of track are of a type commonly knownas absolute signals,that is, these signals must be rigidly, observed by the engineers and should not be passed, when indicating stop or danger, unless with great oare and strictly in accordance with the prescribed rules of safety;

The intermediate signalslO; and 11, however,

areof the type commonly known as permissive signals, that'is, these signals maybe passed, when" lndlcatlngstop or danger, without exerc sing the same degree of care requiredwhen passing the absolute signals 9 and 12.. The different aspects of'the signals 9 and12, and the signals 10' and 11, which are necessary to enable the engineer to differentiate between them, may be ob tamed in various ways; but in the partlcular arrangement illustrated, the absolute sig ..nals 9 andl2 have squared-ended semaphore 7 blades, while the permissive signals 10' and 11 have the endsoftheir semaphore blades pointed. Obviousl lg the different aspects of the absolute signals and the permissive signalsmay be obtained in other ways, asby the addition of other semaphores to the ab solute signals; and also instead of semaphores,lights of different colors or a series I I "of lights havingdifterentlpositions may be used to obtain the different aspects.

Thesesignals may be of any well known and approved type which is used in single track orin double track signaling, and primarily comprises an operating motor of any appropriate construction for moving the semaphore blade from a normal biased p'osi-. tion, which may be termed the stop position,

to an operated position, which may be termed acautlon position, and further comprlses means which is effective upon the proper placing of the semaphore in its iop.

er ated position to retain it in that position, together with suitablecircuit controllers operatedin conjunction with the movementof the'semaphore to control the various operating andiholdmg circuitsfor the signal. In the particular; embodiment of the invention illustrated, the signals shown have a d5. degree 02111131011 13051121011. and a horizontal stop position, this being done in order to avoid the confusion of the extra con" trolling circuits incident to the use of three-position signals or of two two-position slgnals arranged as home and distant signals; but it is to be imderstood that it is fully contemplated according to this invention to use appropriate controlling circuits with each signal whereby the preceding signal is caused to assume a caution aspect, the signals in that case having a vertical position indicating proceed at unlimited speed. In practical installations, other ermissive' signals may be located at the left and ends of the blocks A andBC for governing trafiic in the direction indicated by the arrow Y, and at the righthand ends of the blocks BC and D for governing traflic inthe direction indicated by the arrow X; but since the controlling devices and circuits for theseother si nals can be easily determined by one skilled in the art ofrailway signaling from analogy to the controlling devices and circuits of such signals as are shown, and since the addition of the controlling devices and circuits for these other signals would complicate the drawing materially, it has been deemed best to omit the showing of these other signals from the drawing.

Associated with each signal is a relay, hereinafter termed'a line relay, said relays for the signals 9, 10, 11,and 12 beingdesignated 13, 14:, 15, and 16, respectively. Asso- H ciated with each intermediate permissive signal 10' and 11 1s a relay, here1nafter termed a stick relay, said stic relays .being designated 17. and 18respectively vfor the signals 19 and 11. Also,v associated with each signal is a suitable'source of'electric current, as a battery, said batteries for the signals 9, 10, 11, and 12 being designated 19, 20, 21, and22, respectively; and extending the entire length of the stretch oftrack is a common wire 25 to which one terminal of each of said batteries is connected by two wires. For simplicity the different circuits. hereinaftertraced will be traced from the other terminals of the batteries 19, 20, 21,

and 22 (markedpositive) back to the com- I mon wire '25, it being observed that the common w1re 25 serves to complete these different circuitsin each case.

Although certain relays are herein desig nated'as track relays, certain others as line relays and certain others as stick relays, it is not to be inferred from this that there is in reality any essential or fundamental difference between the relays so designated, be-

cause each of these relays are of the well known and ordinary type used for signaling purposes, and vary, not because ofi' difi'erences lIl their constructiombut rather because of the different uses to which they are The track relays 5 and 8 of the block A and D each have three armatures 34, 35, and 36, and 37, 38 and 39, respectively, which are operated thereby in the well known man-.

ner and which aredesignated according to established convention and, the line relays l3land 16 of the blocks. A and D each have; The

an armature 40 and 41, vrespectively. track relays 6 and 7 of thettrack sections, B

and C have four armatures, 46,47,48 and 49, and 50, 51, 52, and: 583, respectively; and

sections B and C havethree armatures, 54, 55, and 56, and 57, 58, and 59, respectively. In order to make the operation; oiithe system clear two: cases will; beassumed, first, Y

that the train enters the stretch; of track traveling in the direction indicated: by the arrow X; and second that another train at 7 another time. enters the stretch; oii track traveling in the direction indicated by the.

arrow Y. Assuming that the train enters the block A movingv in the direction, of the arrow X, the stretch of trackway being en tirely clear ofother trains, the wheels and aXles of said train being or comparatively low resistancevwill shunt the track: relay 510i? the block A and causeits armatures to,,dropf to their lower position. The armature v35 of the trackrelay 5 in dropping interrupts a normally closed circuit for energlzing" the line relay 13, which circuit is aslfollows Circuit Number One.

Commencing at thepositive terminal ofthe battery 20, conductors 60 61, 62, and 63, armature 47 of the line relay 14 in itswupper position, conductors 64 and. 65, armature 35 in its upper position, conductor 66, line relay 13 and conductors 67, 68, and '27 back. to the common wire 25. a i

The supply ofcurrent t0 the line relay 13 being interrupted, the armature 4O ofthis relay drops and interrupts a normally closed circuit which supplies current to themotor; of the signal 9 to holdthat signals in its operated position, thereby causing said signal to assume its biased stop aspect. This cir cuit may be traced as follows:

Circuit Number Tum. I Commencing at the battery 19, conductors and 71, armature 40 of the line relay 13'" in its upperposition, conductor 72, signal9, v68, andn26 back to the bat conductors 73,

The dropping oftheiarmature 34 of the track relay 5 interrupts a normally. closed circuit for supplying current to the line relay 15 associated with the signal 11, said circuit being as follows:

Oz'rcuz't 1V umber hmee.

Commencing at the battery 19, conductors 70, 7 4, and7 5 armature 34 ofthe track relay 5 inits upper position, conductorw7 6, armae as follows a ture, 56 of the stick relay 17 in its lowerpol- ,sition, conductor 77, armature 42 of the track relay 6 in it'stupper position, conductor 78, armature 45 of the track relay 7 in being Clltl off, the armature- 50, of this relay eachof the stick relaysi17 and 18 of theltrack will drop andzinterrupt the circuit which normally supplies current to thel signal ll:

and holds said signal in its: operated posi- 'tion, thereby causing said signal to assume its .biasedstop. position, said circuit being Commencing at; thetbattery- 21,,1conductors 83, 84, and 86, armature 50 of the line relayw1 5 in its upper" position, conductor 8",

: -signal 11 and conductors 88,781, 82-and31 back i to V the common wire 25.

When the line relay 15 is deenergized, its

armature 51 drops and interrupts a circuit Number Five for normally energizing the line relay 16, which circuit maybe traced-as follows: a

Circuit Number Five.

its upper position, conductor 92, line relay 16, and conductors93, 94%anda33 back. to the,

common wire 25. y a

The line relay*16 beingadeenergized, its

armature 4l-drops andointerrupts a circuit signal12 and holdsit in itsoperated; position, thereby causing said signah12 to as a Number Six which suppliescurrenttothe:

some its biased stop position, said circuit Number Six for thevsignal l2being as follows:

ama Num er sa.

battery 22.,

From the foregoing canwbe seemthat when the tra1n-enters thestretch of single 1 track mov ng in the direction. indicated by;

the arrow X, thesignaln9 behind, thetrain will assume the stop or dangeraspect and the, two signals 11 and 121gover1iing-"traific their stop aspects. The signal l2prevents head-on protection, while the signal 9 gives the train followingprotection, When the train enters the block A deenergizes the r a l Commencing at thebattery 22, conductors 95 and 96, armature 41 of the line relay 16 in. its upper position,vconductor 97, signal: 12, ,and conductors 98, 94 and 82back to the 1 V in the opposite direction will also assume I 95, 110, and 111, armature 37 to the track relay 8 in its upper position, conductor; 112, armature 59 of the stick relay-18- in" its lower position,"'conductor .113,"armatrack relay 5, the armature 36 of said track" Commencing at the battery 19, conductors relay drops and closes a preliminary enerb cult is as follows:

ized circuit for the stick relay 17 which cire p p v v 28 back to the battery 20. k a

a When the armature 48 of the line relay ircm't N umber Sew-c t. I

70, 74, and 100, armature 36 of the track relay-5 in'it'slower position, conductors 101 and 102 armature 48 of the line relay 14 in its upperposition, conductors 103. and 104,

stick relay :17 and conductors 105, 106 and 29 backto the common wire25. 1

The energization of the stick relay 17 raises its armature 54 and completes amaintaining circuit for said stick relay 17 as folcommon wire 25.

Commencing at the battery 19, conductors 70, 74, and 100, armature 36 of the track relay 5 in its lowerposition, conductors 101, 107 and 108, armature 54'of the stick relay 17, conductors 109 and 104, stick relay 17, and conductors 105,106 and 29 back'to the When the first pair of Wheels and axle of the train enter the track section B, the track relay 6 is shunted and its armatures drop The armature 42 opens another break in the V circuit Number Three andmaintains the line :Number Three hereinbefore set forth, as

follows: I s

' Uc'rcm't Number Nine.

Commencing at the battery 22, conductors ture 44 of the'track relay 7, conductor 114,

, armature 43 of the track relay 6 in its upper position, conductor 115, line relay 14, conductors 116, 117, 106, and 29 back to the common wir'e25. V

The deenergization of the line relay 14 causes its armature 46 to drop and interrelay 60, 61, 62, and 118, armature 46 of the line line relay 14 completes another maintaining circuit for the stick relay 17-as follows: Circuit N umber Zoen.

Commencing at the battery 20, conductors '60, 61, and 121, armature-49 of the'line 14 invits lower position, conductors 122 and 108, armature 54 of the stick relay 17 inits upper position, conductors 109 and 104, stickfrelay 17, and conductors 105, 10 and 29 back to the common wire 25.

The armature 47 of the line relay 14 in dropping would interrupt the circuit Nu1n ber One for the line relay 13,except forthe fact that the stickrelay 17 is energized and its armature 55 is in its upper position, so as to complete a shunt comprising the con- 1 ductors 123 and 124 for the contacts of said armature 47, so that when the train hasentirely left the block A and the track relay 5 has been energized toraise its-armature 35, current canfiow from the battery 20 and "energize the line relay along-a circuit as follows: A a

oamazv mbae Twelve; Commencing at the battery 20, conductors 60 position, conductor 66, line relay1'3 andconductors 67 68,:and27 back to the common wire '25. I a

'When the line relay .13 is energized its armature 40"is'raised to close the circuit 7 Number Two and causesthe signal 9to' as sume its operated position, thereby permitting another following' train' to enter'ithe block A. 1

;. It should be noted that the armature 56 "of the stick relay 17 opens a break in the circuit Number Three for energizing theline relay 15 so that said line relay 15 remains and 123, armature '55 of the stick relay 17 inits upper position, conductors 124 and 65, armature35 of the track relay 5 in itsiupper deenergizedand the signals ll and 12icontrolled thereby will remain in their'sto position until the maintaining circuitum ber Seven for the stick relay is broken by in dropping makes another break in the circuit Number Five forenergizing the line V entirely left the track section B.

' relay 16, so that said line relay 16 will'remaindeenergized and thesignal12 will m: i "mainrln its stop rpositionafter the train has When the first pair of wheels and axle of the train enter the block D the track relay 8 is deenergized, and its armature 37 in dropping opens a break in the circuit Number Nine for energizing the line relay 14, so that said line relay will remain deenergized, and the signal 10 will remain in its stop position until the train has entirely left the block D. The armature 38 of the track relay 88 maintains the circuit Number Five for the line relay 16 broken and the signal 12 in its stop position until the train has entirely left the block D. The dropping of the armature 39 of the track relay 8 has no effect since the preliminary energizing circuit for the stick relay 18 is broken at the armature 52 of the line relay 15.

When the'last pair of wheels and axle of the train leave the block D, the track relay 8 is renergized andits armatures are raised to their upper position to restore all of the parts of the system to their normal positions.

When another train enters the stretch of track in the direction indicated by the ar row Y, the effect produced upon the different signals controlling traffic in the direction in which the train is traveling and in the opposite direction is substantially the same as the effect produced by the train traveling in the direction indicated by the arrow X; and the diiierent circuits broken and established can be easily traced by analogy to the circuits already traced. When the train moving in the direction indicated by the arrow Y enters the block D, its wheels and axles shunt the track relay 8; and the armature 37 of said track relay 8 drops and interrupts the circuit Number Five for energizing the line relay 16, whereupon the armature 41 of said line relay 16 drops and interrupts circuit Number Six for the signal 12 and causes said signal 12to assume its stop position. The armature37 of the track relay 8 drops and interrupts the circuit Number Nine for energizing the line relay 14, and the armature 46 of said line relay 14 drops and interrupts the circuit Number Ten for the signal 10 and causes said signal 10 to assume its stop position. The armature 47 of the line relay 14 drops and interrupts the circuit Number One for energizing the line relay 13, whereupon the armature 40 of said line relay 13 drops and interrupts the circuit Number Two for the signal 9" and causes the signal 9 to assume its stop position;

From the foregoing it can be seen that when a train enters the stretch of single track traveling in the direction indicated by the arrow Y, the opposing signals-9 and 10 are placed at danger to furnish head-on protection for the train, and the signal 12 is placed at danger to afford. following protection for the train Iii ' When the armature 39 of the track relay 8 drops it closes a preliminary energizing circuit for the stick relay 18, said circuit being as follows:

Circuit Number Thirteen.

Commencing at the battery 22, conductors 95, 110, and 125, armature 39 of thetrack relay 8 in its lowerpositi'on, conductors .126 and 127, armature 52 of the line relay 15 in its upper position, conductors 128 and 129,

stick relay18, conductors 130, 82, and 31 back to the common wire 25. I

hen the stick relay 18 is energized its armature'57 is raised to complete a maintaming circuit for said relay as follows:

Circuit Number F owteen.

Commencing at the battery 22, conductors 95, 110, and 125, armature 39 of the track relay 8 in itslower position, conductors 126, 131', and 132, armature 57 of the-stickrelay 18 in its upper position, conductors 133 and 129,stick relay 18 and conductors 130, 82, and: 31 back to the common wire 25.

As the train progresses and enters the track section C,the track relay 7 is shunted and its armatures 44 and 45 drop to their lower positions. The armature 44 opens another break in the circuit Number Nine for came Number Fifteen.

Commencing, at the battery 21, conductors 83, 84, and 134, armature 53 of the line relay 15 in its lower position conductors 135 and 132, armature"?!- of the stick relay 18in its upper position, conductors 133 and 129, stick relay 18 and conductors 130, 82, and 30 back tothe battery 21. r

The foregoing circuit Number Fifteen maintains the stick relay energizedas long as the line relay'15 is deenergized,and from circuit Number Three it can be seen thatthe line relay 15 will remain deenergized until the train has passed through the entire length ofthe stretch and has left the block A. When thetrain in question moving in the direction indicated" by the arrow Y passes from the block 1) into thevtrack sec=' tion C and deenergizes the line relay'15, the armature 51 of said line relay 15 opens another break in the circuit Number Five for energizing the line relay 16, and would hold the signal 12 at danger if it were not for has left the block A.

the stick relay 18, but whensaid stick relay 18 is energized its armature 58 is raised to establish a shunt, comprising conductors 136 and 137, for the contacts of the armature 51 of the line relay 15 so that, in spite of the fact that the line relay 15* is deenergized, the line relay 16 can be energized to cause the signal 12 to assume its operated proceed position by a circuit as follows:

Circuit N umber Sixteen.

Commencing at the battery 21, conductors 83 and 137, armature 58 of the stlck relay .18 in its upper position, conductors 136 and 91, armature 38 of the track relay 8 in its upper position, conductor 92, line relay 16 and conductors 93, 94, and 33 back to the common wire 25.

It-should be noted that when the train enters the stretch of track traveling in the direction indicated by the arrow X, the signal 9assumes its proceed position as soon as the train entlrely leaves the block A,

position, whereas in the other case, when the-train is traveling in the'direction indicated by the arrow Y the presence of the train on the track section B holds the signal 9 in its stop position. These different controlling effects on thesignal 9 produced by the track relay 6 of the track section B, depending upon the direction in which the train, is traveling when it enters the track section B, is due to the operation of the stick relay 17 and since the more significant features of this invention reside in the controlling circuits for the stick relays 17 and 18, these controlling circuits for the stick relay 17 have been drawn in heavy lines, it being noted that the controlling circuits for the stick relay 18 are the same. Referring to these circuits drawn in heavy lines it can be seen that the preliminary energization of the stick relay 17 is dependent upon'the condition of the track relay 5 and the line relay 14, the energizing circuit for said relay beingestablished when thetrack relay 5 is deenergized and the line relay 14 is energized, The line relay 14 is controlled by the track relay 6 of the track section B, and is deenergized when said track relay is deenergized. In short, if the train enters the blook'A-from thetrack section B the'stick W henthe stick relay 17 is energized by the dropping of the armature 35 of the track relay 5, a maintaining circuit is immediately established, said maintaining circuit being controlled independently of the armature 48,

of the line relay 14 which is included in the reliminar ener izin circuit for said stick P t: b

relay 17. When the line relay 14 is deenerglzed its armature 49 establishes another maintaining circuit for the stick relay 17,

so that said stick relay 17 remains energized until said line relay 14 is reenergized. During the time that the armatures of the line relay 14 are dropping and during the time that the preliminary energizing circuit 5 for the stick relay 17 is broken and before the other maintaining circuit Number Eleven for said. stick relay is established, said stick relay is held up by the first maintaining circuit Number Eight. This particular arran ement of two maintaining circuits may be eliminated if makebefore-break contacts are used so that the armature 49 contacts with the conductor 119 before the armature 48 breaks contact with the conductor 103 when the line relay 14 is deenergized; Other features of the controlling circuits can be readily seen without being specifically pointed'out.

In case two trains moving in opposite directions should happen to enter the blocks A and D simultaneously both the signals 10 and 11 would be placed in their stop positions, so that each train would receive headon protection.

Although the particular embodiment of the invention shown is designed to be operated by direct current, simple modifications, which will be apparent to those skilled in theart of railway signaling, may be made whereby alternating current may be used as the operating medium. Also, the number of track sections into which the stretch of single track is divided may be different according to different conditions; and other signals protecting the sidings, preliminary sections, and'other' different expedients knownin the art of railway signaling may be combined with this invention without departing from it or from the, particular physical embodiment thereof shown and described.

Although I have particularly described the construction of one physical embodiment of my invention, and explained the operation and principle thereof," nevertheless, I desire to have it understood thatthe form selected is merely illustrative, but does not exhaust the possible physical embodiments of the idea of means underlying my invention.

What I claim as new and desireto secure by Letters Patent of the United States, is:

1. In a signaling system for railways, in

' combination; a stretch oftrackway; a signal for governing trafiic in one direction over said stretch, said stretch being divided into a first block protected by said signal and a second block following said first block, each of said blocks being track circuited and having a track relay; a circuit for controlling said signal; a circuit controller included in said controlling circuit and controlled by the track relay of said second block so as to be opened when said track relay is deenergized; a normally open shunt for the contacts of said circuit controller; a relay having cooperating contacts operated thereby which are includedin said shunt and which are closed when said relay is energized; a preliminary energizing circuit for said relay controlled jointly by the track relays of said first block and said second block and closed when the track relay of said first block is deenergized and the track relay of said second block is energized;a maintaining circuit for said relay including cooperating contacts operated by said relay itself and closed when said relay is energized; said maintaining circuit being a branch of said preliminary energizing circuit and being controlled by the track relay of said first block independently of the track relay of said second block; another circuit controller controlled by the track relay of said second block and closed when that track relay is deenergized; and another maintaining circuit for. said relay including said cooperating contacts thereof and said another circuit controller.

2. In a block signal system for railroads having tracks divided into track sections each having a track relay, a signal, a line circuit controlled by the track relays of a plurality of track sections in advance of the signal, a stick relay, an energizing circuit for the stick relay controlledby said line circuit and the track relay of a track section next in the rear of said signal, a preliminary stick circuit controlled by said rear track section, a final stick circuit controlled by said line circuit, and a circuit for controlling a signal in the rear governed by the line circuit and the stick relay jointly.

3. In a block signal system for single track railroads, three adjacent track sections each having a track relay, a stick relay, a pick-up circuit for the stick relay controlled by the track relays of two adjacent track sections, a preliminary stick circuit controlled by one of said two track relays, and a final stick circuit controlled by the other of said two track relays and the track relay of the third track section.

4:. In a signaling system for railways, in combination; a stretch of trackway divided into a first and a second track circuited block each having a track relay; a signal at the entrance to the first block for governing traflic in one direction; a circuit controller controlled by the track relay of said second block and opened when said track relay is .deenergized; a circuit for controlling said signal including said circuit controller; a normally open shunt circuit for the contacts ofsaid circuit controller; a relay 'havingcooperating contacts operated thereby which are included in said shunt circuit and which are closed when said relay is energized; a preliminary energizing circuit for said relay; and a maintaining circuit for said relay including said cooperating con tacts operated by the relay itselfand closed when said relay is energized, said maintaining circuit being controlled by the track relay of said first block independently of the track relay of said second block.

5. In a signaling system for railways, in combination: a stretch of track divided into track circuit sections; a'signal for governing traflic over said-stretch and protecting a pre determined portion thereof; a signal circuit for said signal controlled by the track relays associated with said portionof the stretch;

a circuit controller included in said signal circuit and controlled by thetrack relays of another portion of said stretch in advance of said first mentioned portion in the direction in which said signal governs trafiio; a shunt for said circuit controller; a stick relay for closing said shunt when energized; an BHBIglZlIlg circuit 'for said stick relay which is closed when said first mentioned portion of the stretch is occupied and said second mentioned portion is not occupied; a preliminary stick circuit forsaid stick relay which is closed when said first mentioned portion of the stretch is occupied and said stick relay is energized; and another stick circuit for said stick relay which maintains said stick relay energized after it has been preliminarily energized so long as any part of said second mentioned portion of the stretch is occupied by a train.

6. In a signaling system for railways, in combination: a relay, two circuit controllers; an energizing circuit for said relay including said circuit controllers; cooperating contacts operated by said relay and 7. In a slgnaling system for railways, in

' associated with each signal; a signal circuit for controlling each signal relay which is controlled by the track circuit sections protected by the corresponding signal and also by the signal relay of the signal next in advance governing trafiic in the same direction; an auxiliary relay associated with each intermediate signal for controlling the. signal circuit of the signal next in the rear independently of the signal relay of that intermediate signal; means associated with each auxiliary relay for preliminarily energizing'it when a train traveling in the direction of trafiic governed by the corresponding signal occupies a track circuit section in the rear of the corresponding signal prior to occupying a track circuit section in advance of the corresponding signal; and

'means for maintaining said auxiliary relay energized after it has been preliminarily energized by said last mentioned means while a train occupies said track circuit section in the rear and also the track circuit sections in advance of the corresponding signal and protected thereby.

'8. In a signallng system for railways, in combination: a plurality of track circuit sections; a line relay controlled by certain of said track circuit sections; a circuit controller controlled by said line relay; a second circuit controller governed by a track circult section 1n the rear of sald certain track sections; stick relay; an energizing circuit for said stick relay including said circuit controllers; a preliminary stick circuit for said'stick relay including said second circuit controller; a third circuit controller governed by said line relay and closed when that relay isdeenergized; another stick circuit including said third-circuit controller; and a circuit for signaling controlled by said stick relay. I

9. In a railway signaling system, a plurality of track circuit sections, a normally closed circuit controller opened when either of two particular track circuits is shunted, a normally open circuit controller governed by a track circuit adjacent to said particular track circuits, a stick relay, an energizing circuit for the stick relay including said circuit controllers ,in series; a shunt for the normally closed circuit controller established by the energization' of the stick relay, and

means for maintaining said stick relay energized after it has been initially energized so long as either of saidtwo particular track circuits is shunted.

10. In a railway signaling system, the combination with a stretch of track divided into track circuit sections, signals at intervals for governing traffic in one direction, a signal circuit for each signal, astick relay associated with an advance signal for corn trolling the signal circuit of the signal next in the rear, means for energizing the stick relay of said advance signal upon the approach of a train thereto which is traveling in said direction of traffic, and separate means for maintaining said stick relay energized which are operated successively by such train, one means being operated as the train approaches the advance signal, and the other means after the trainhas passed that signal.

, FRANK 'L. nonesoN. 

